Ureteral stents are commonly used for the treatment of renal diseases and conditions, such as kidney stones. Once implanted, the stent extends through the ureter from the kidney to the bladder, maintaining patency of the ureter and permitting drainage. The placement of a ureteral stent often causes side effects for the patient, such as bladder pain, discomfort, urinary urgency, or urinary frequency. Currently, these side effects are treated with oral therapies, such as narcotics, alpha blockers, and antimuscarinics. Efficacy is variable, and treatment-limiting side effects occur. Some drug-coated ureteral stents have been employed for local drug delivery, but such known stents generally have a relatively small drug payload and cannot deliver an effective amount of drug in a controlled manner over an extended period of time.
For example, U.S. Pat. No. 7,862,552 to McIntyre et al. discloses a ureteral stent having a drug-eluting region. The drug-eluting region comprises a drug contained within a polymeric matrix. Although such drug-eluting ureteral stents have demonstrated some improvements in reducing pain associated with the use of the ureteral stent in a subset of patient populations, in clinical trials, one such drug-eluting stent “did not demonstrate a clear advantage in reducing the number of unscheduled physician contacts, early stent removals, pain medication changes, or patient assessed pain [Visual Analog Score].” See Krambeck et al.: A Novel Drug Eluting Ureteral Stent: A Prospective, Randomized, Multicenter Clinical Trial to Evaluate the Safety and Effectiveness of Ketorolac Loaded Ureteral Stent; The Journal of Urology; March 2010; 183: 1037-43.
It therefore would be desirable provide improved ureteral stents and methods for treating pain and other side effects associated with the implantation of a ureteral stent in patients. It also would be desirable to delivery a drug to the bladder for any other treatment purpose in conjunction with the deployment of a ureteral stent in a patient.